Injection tools are used in mining industry. When, for example, tunnels are mined through rock it is necessary to seal all cracks in the surrounding rock material to avoid water leaking through the cracks or prevent loose parts of the rock material coming out of the walls. This kind of sealing of the tunnel walls is done by drilling large number of boreholes to the surrounding rock material. Into these boreholes injection tools are inserted and secured to the holes. Through these injection tools appropriate concrete or other similar liquid material is injected. The injected material is penetrating into the cracks of the rock material and when the liquid material has become hard the tunnel will be safer concerning any falling rocks from the ceiling. This kind of procedure prevents also surrounding groundwater entering the tunnel, which is also used in underwater constructions.
The boreholes which are used for the injection are typically a few meters deep but they can also be as deep as 10-20 meters. In that case the point of the injection tool is inserted to the borehole and the injection tool is secured to its place with multiple washers which are pressed against the walls of the borehole. These washers keep the injection tool in its place and prevent the injected liquid material flowing out of the borehole. The pressures used for the injection are high so that the liquid material fills all cracks and seals them. High pressures mean also high risks to the safety of the workers. If the washers slip in the borehole the entire injection tool is “shot out” from the borehole and could cause severe injuries to the workers. It is not possible to tighten the injection tool after the injection is started. The tightening of the injection tool to the borehole is done by hand. It is hard work in a challenging environment and therefore this procedure is highly exposed to human errors. There is a typically a hand operated valve at the end of the injection tool close to the connecting piece which connects the injection tool to the injection machine.
When the injection is done the valve in the injection tool is closed and the injection tool is left in the borehole until the injected liquid material is hardened. The injected material is hardening also inside the injection tool and in the borehole if there are any leaks through the sealing washers. Therefore the injected material is also gluing the injection tool to the borehole. This is problematic if there is a need to bore the borehole open for another injection in case the first injection does not seal the surrounding rock material completely. It is much more difficult job to drill through the injection tool than it is to drill through the hardened sealing material.
It is also expensive to use one injection tool for every borehole, because at a typical working site there can be thousands of boreholes used for the injection. This also involves a lot of injection tools to be transported to the working site when it can be a long way underground.
If the separation of the injection tool from the borehole will succeed the tool is filled with hardened injection material. It is not possible to clean the tool for further use. The tool is simply not reusable.
The drawbacks and problems of the prior art solutions are:                the injection tool is disposable        the borehole is not reusable        cannot be reassembled if the sealing between the injection tool and the wall of the borehole is leaking        hand tightened injection tool        high material traffic to the working site.        